Telescopic compensating unit



y 1961 0. HOFFLIN 2,991,971

TELESCOPIC COMPE"\L'SAT1NG UNIT Filed Feb. 11, 1958 INVENTOR. OTTO HOFFL! N 'S A TTORNEYS "this cylinder through a passage Patented July 11,1961 tic This invention relates to compensating units for receiving acontinuous flow of viscous material and delivering the collectedmaterial intermittently and, more particularly, to a new and improvedcompensating unit arranged to eliminate loss of the viscous material.

In apparatus for handling viscous material under pressure, compensatingdevices for coupling continuous and intermittent flow stages are wellknown. Many of these devices such as the device described in the UnitedStates patent to Wilson et al. No. 2,474,136, for example, include anaccumulating cylinder supplying material from a continuously operatingproduction stage to an intermittent packaging stage and a piston movablewithin the cylinder under controlled pressure. Viscous material from thecontinuous stage is customarily received through an aperture in thepiston and distributed thereby in a uniform manner at the end of thecylinder opposite the intermittent stage, a telescopic connection beingprovided in the supply line to accommodate the movement of the piston.Inasmuch as the viscous material flows through the apparatus underpressure, some'of the material being processed inevitably leaks outbetween the sliding members of the telescopic connection in the supplyline, resulting in substantial contamination or loss of the material.

Accordingly, it is an object of the invention to provide new andimproved apparatus for handling viscous material arranged to preventloss of material by leakage from the supply line.

Another object of the invention is to provide apparatus of the abovecharacter wherein any material leaking through the telescopic connectionis not wasted.

These and other objects of the invention are attained by supplying theviscous material through a fixed tube to a telescopic connection withinthe accumulating cylinder. From the movable part of the telescopicconnection the viscous material is delivered to the operating surface ofthe piston for distribution across the end of the cylinder opposite theintermittent stage in the usual manner.

Further objects and advantages of the invention will be apparent from areading of the following description with reference to the accompanyingdrawing in which:

FIG. 1 is a longitudinal section through a typical compensating unitarranged in accordance with the invention; and

FIG. 2 is a cross sectional view taken on the line 2-2 of FIG. 1 lookingin the direction of the arrows.

As illustrated in FIG. 1, a representative embodiment of the inventioncomprises an accumulating cylinder 1, open at both ends and having atone end a flanged orifice 2 which may be connected to apparatus, such asa packaging device (not shown), intermittently accepting viscousmaterial from the cylinder. At its other end the accumulating cylinder,which terminates in a flange 3, is connected by distance-bolts 4 to apressure cylinder 5 in coaxial alignment, pneumatic pressure beingsupplied to 6 in a cover 7 closing the end of the cylinder away from theaccumulating cylinder.

In order to transmit the pneumatic pressure to the viscous materialwithin the accumulating cylinder 1, a freely movable piston 8 ispositioned within the accumulating cylinder and connected bylongitudinal shafts 9 to a piston 10 movable within the pressurecylinder 5, each piston being provided with suitable packing to form afluid-tight seal with the corresponding cylinder. Viscous material iscontinuously supplied to the compensating unit under pressure through atube 11 which passes through an opening in the side of the accumulatingcylinder 1 and is sealed therein by a weld 12, the inner end 13 of thetube 11 being positioned coaxially with the cylinder and directed towardthe piston 8. Telescopically engaging the end 13, a hollow tube 14 leadsthrough a socket 15, by which it is aflixed to the piston 8, to aseriesof radial channels 16 which distribute the viscous material across theworking face of the piston, thus assuring uniform spreading of thematerial over the cross section of the piston 8. In order to accommodatethe full stroke of the piston 8, the tube 14 and the coaxial end of thetube 11 are made at least as long as the distance-bolts 4, whichdetermine the maximum stroke.

Leakage of the viscous material between the sliding surfaces of thetubes 13 and 14 is substantially eliminated by a gasket 17, but it willbe noted that inasmuch as the accumulating cylinder 1 is filled with thesame material during operation, any substance which does leak out is notlost but mingles with the material flowing toward the orifice 2.Further, it will be observed that the tendency for material to leakthrough the telescopic connection is, in this case, greatly reduced ascompared with compensating units wherein the telescopic connection isoutside the accumulating cylinder, since the pressure of the materialsurrounding the connection is substantially the same as that within thesliding tubes.

As best seen in FIG. 2, a block 18, clamped to two of the rods 9,supports a longitudinal shaft 19 which passes along the outside of theaccumulating cylinder and has two spaced rollers 20 and 23 affixed atthe opposite end. Positioned between the rollers an arm 21 is arrangedto operate a valve 22 controlling the supply of the material to the tube11. When the block 18 is against the flange 3 the arm 21 is moved by theroller 23 so that the valve 22 is fully opened. As the block 18 travelsaway from the accumulating cylinder the shaft 19 first brings the roller20 into contact with the arm 21 which then gradually closes the valveuntil it is completely shut when the block 18 meets an abutment plate 24adjacent the pressure cylinder 5, thus preventing overloading of theaccumulating cylinder.

In operation, viscous material is continuously supplied to the tube 11and pneumatic pressure is applied to the piston 10. This pressure istransmitted through the shafts 9 and the piston 8 to the material withinthe accumulating cylinder 1, forcing it out through the orifice 2whenever the intermittent stage is in condition to receive it. If thequantity of material supplied to the tube 11 over an interval of time isgreater than the quantity discharged in this manner, the piston 8progresses toward the cylinder 5, moving the arm 21 by means of theshaft 19 to reduce the supply of material. On the other hand, the shaft19 moves the arm 21 to increase the flow when the amount forced throughthe orifice 2 is greater than the supply. Under the usual operatingconditions, however, when the flow has been automatically adjusted inthis manner, the piston 8 moves back and forth within a limited rangeduring each delivery cycle so that neither of the spaced rollers 20 and23 actuates the control arm 21.

It will be understood that the embodiment described herein isillustrative rather than restrictive of the invention. Accordingly,various modifications and changes therein will occur to those skilled inthe art which do not exceed the intended scope of the invention asdefined by the following claims.

I claim:

1. Apparatus for coupling in a flow system, said apparatus comprisingmeans forming a chamber having an inlet means and an outlet means, apiston movable within the chamber to vary the capacity thereof, saidpiston having a working face, means for applying a force to urge thepiston in a direction to decrease the capacity of the chamber, saidinlet means including a first fixed tube leading into the chamber andincluding a portion parallel to the direction of motion of the piston,and a second tube fixed to the working face of the piston and slidablyengaging said portion of the first fixed tube, said second tube havingport means opening from the interior thereof to said chamber closelyadjacent to the working face of the piston.

2. Apparatus according to claim 1 wherein the second tube is aflixedcentrally to the Working face of the piston and the port means comprisesa plurality of radial channels angularly disposed about the end of thesecond tube.

3. Apparatus for coupling in a flow system, said apparatus comprisingmeans forming a chamber having an inlet means and an outlet means, apiston movable Within the chamber to vary the capacity thereof, saidpiston having a working face, pressure means for urging the piston in adirection to decrease the capacity of the chamber, said inlet meansincluding a first fixed tube leading into the chamber and including aportion parallel to the direction of motion of the piston, and a secondtube fixed to the Working face of the piston and slidably engaging saidportion of the first fixed tube, said second tube having port meansopening from the interior thereof to said chamber closely adjacent tothe working face of the piston.

4. Apparatus for coupling in a flow system, said apparatus comprisingmeans forming a chamber having an inlet means and an outlet means, apiston movable Within the chamber to vary the capacity thereof, saidpiston having a working face, pressure mean normally urging the pistonin a direction to decrease the capacity of the chamber, said inlet meansincluding a first fixed tube leading into the chamber and including aportion parallel to the direction of motion of the piston, and a secondtube fixed to the working face of the piston and slidably engaging saidportion of the first fixed tube, said second tube having port meansopening from the interior thereof to said chamber closely adjacent theWorking face of the piston, and control means in said inlet means, saidcontrol means operatively associated with the piston so as to beresponsive to the position thereof to regulate flow through the inletmeans.

References Cited in the file of this patent UNITED STATES PATENTS295,532 Francis Mar. 25, 1884 540,003 Reed May 28, 1895 726,155 FultonApr. 21, 1903 1,010,834 Westburg Dec. 5, 1911 1,885,000 Muller Oct. 25,1932 2,474,136 Wilson Jan. 2l, 1949

